VARIATION OF DISORDER IN SUPERCONDUCTING GLASSY METALS

The impact of increased disorder on superconducting T(c) and H(c2) of amorphous Zr-Cu and Hf-Co has been studied. In these highly disordered materials, disorder was incrementally increased by irradiation with f ast neutrons of low intensity. Increased resistivity, increased magnit ude of drho/dT, and smearing of the x-ray-diffraction patterns, confir m the increased disorder. The irradiation effects on rho and T(c) depe nd on the amorphous system, but when the T(c) depression is plotted vs resistivity increase, all data fall on the same curve. T(c) data are well described by the Fukuyama-Ebisawa-Maekawa theory. The normalized critical field h(t) increases at low temperatures with increasing dis order. This cannot be explained by present theories.